Shock absorbers for vehicles

ABSTRACT

A shock absorber comprising a cylindrical body closed at both ends, a plunger disc lying within and across said cylindrical body in a plane perpendicular to the axis of said cylindrical body, said plunger disc being in sealed but slidable contact with the inner surface of said cylindrical body, a plunger rod connected at one end to said plunger disc substantially at the center of said plunger disc, said plunger rod extending through one end of said cylindrical body and being adapted at its other end for connection to a vehicle supporting or conveyancing member of said vehicle, said cylindrical body being adapted at the end thereof opposite to the end through which said plunger rod extends, for attachment to the other of said vehicle supporting or conveyancing members, and at least one coil spring substantially concentrically aligned with the axis of said cylindrical body and lying within said cylindrical body, said coil spring extending between said plunger disc and the inner surface of an end of said cylindrical body.

United States Patent Papousek 51 Aug. 8, 1972 [54] SHOCK ABSORBERS FORVEHICLES [72] Inventor: Robert D. Papousek, 3233 East Third, Tucson,Ariz.

[22] Filed: Sept. 14, 1970 [21] Appl. No.: 72,019

l,207,426 12/1916 McNabb ..268/34 Primary Examiner-James B. MarbertAttorney -M. N. Cheairs and C. Ray Holbrook ABSTRACT A shock absorbercomprising a cylindrical body closed at both ends, a plunger disc lyingwithin and across said cylindrical body in a plane perpendicular to theaxis of said cylindrical body, said plunger disc being in sealed butslidable contact with the inner surface of said cylindrical body, aplunger rod connected at one end to said plunger disc substantially atthe center of said plunger disc, said plunger rod extending through oneend of said cylindrical body and being adapted at its other end forconnection to a vehicle supporting or conveyancing member of saidvehicle, said cylindrical body being adapted at the end thereof oppositeto the end through which said plunger rod extends, for attachment to theother of said vehicle supporting or conveyancing members, and at leastone coil spring substantially concentrically aligned with the axis ofsaid cylindrical body and lying within said cylindrical body, said coilspring extending between said plunger disc and the inner surface of anend of said cylindrical body.

9 Claims, 2 Drawing Figures 1 srrocx ABSORBERS roa VEHICLES BACKGROUNDOF THE INVENTION The present invention relates to a new and improvedshock absorber for motor vehicles. Particularly, the present inventionis concerned with a shock absorber to be used on either the front orback of motor vehicles to act in tension as well as compression.

Generally, suspension units for motor vehicles include a telescopichydraulic shock absorber for heavy loads. In circumstances where avehicle suspension already incorporating telescopic shock absorbersproves unsatisfactory in use because it is too soft for the loadconditions which it experiences, then combined suspension units areuseful in enabling the vehicle suspension to be stiffened or otherwisemodified without major structural changes, simply by directly adding acoil spring, sometimes called an overload spring, externally around theshock absorber to act in compression. This is frequently employed onpick up trucks used for heavy loads or for campers installed on pick uptrucks. Frequently, this so-called overload spring is used onautomobiles or station wagons for supporting trailers or heavy loads onthe back, for instance, a new type of camper designed to be carried on astation wagon. In nearly all cases, the compression overload springs areinstalled on the rear shock absorbers to support the heavy rear load.

The purpose of all automobile and other vehicle suspension systemsbetween the wheels and the frame of the automobile or other vehicle isto support the vehicles body and frame upon the wheels and provide themeans of absorbing road shock caused by passage of the wheels overirregularities. In general, there are four major types of springs usedfor such suspension. These are leaf springs, coil springs, torsion barsprings and air or liquid hydraulic springs. The weight of theautomobile or other vehicle applies on initial compression to thesprings and when the wheels encounter irregularities in the highway orearth surface, the springs further compress to absorb additional shock.The springs may, also compress considerably due to heavy loading of thevehicle or due to banking or leaningof the vehicle during thenegotiation of turns or curves at high speed. Shock absorbers are usedas noted above, in conjunction with or as a replacement for springs torestrain excessive spring movement and prevent prolonged oscillations,which would afford a generally rougher ride. The most serious problem,however, with all the various types of suspension systems for vehicleseither as a spring of the type mentioned above or a combination ofspring and shock absorber for heavy loads is that the front, inparticular, of the automobile or other vehicle always rides high and hasa definite tendency to bounce when passing over highway or earthsirregularities thereby creating an uncomfortable ride resulting in poorcontrol of the vehicle.

It is now an object of the present invention to provide an improvedsuspension system for vehicles.

An additional object of the present invention is to provide an improvedsuspension system for vehicles which operates in tension as well as incompression thereby equalizing the front and rear levels of a heavilyloaded vehicle.

A particular object of the present invention is to provide a new andimproved shock absorber which may be used on either the front or therear of a vehicle and which operates in tension as well as compressionand which substantially alleviates the problem of uncomfortable ride andpoor control due to the front end of heavily loaded vehicles ridingsignificantly higher than the rear end thereof.

Additional objects will become apparent from the following descriptionof the invention herein disclosed.

SUMMARY OF THE INVENTION The above and other objects are accomplished bythe present invention which is a shock absorber comprising a cylindricalbody closed at both ends, a plunger disc lying within and across saidcylindrical body in a plane perpendicular to the axis of saidcylindrical body, said plunger disc being in sealed but slidable contactwith the inner surface of said cylindrical body, a plunger rod connectedat one end to said plunger disc substantially at the center of saidplunger disc, said plunger rod extending through one end of saidcylindrical body and being adapted at its other end for connection to avehicle supporting or conveyancing member of said vehicle, saidcylindrical body being adapted at the end thereof opposite to the endthrough which said plunger rod extends, for attachment to the other ofsaid vehicle supporting or conveyancing members, and at least one coilspring substantially concentrically aligned with the axis of saidcylindrical body and lying within said cylindrical body, said coilspring extending between said plunger disc and the inner surface of anend of said cylindrical body. In a particularly useful embodiment of thepresent invention, a pair of coil springs is provided within saidcylindrical body, said pair of coil springs being substantiallyconcentrically aligned with the axis of said cylindrical body, one ofsaid coil springs surrounding said plunger rod and extending betweensaid plunger disc and the inner surface of the end of said cylindricalbody through which said plunger rod extends, the other of said coilsprings lying within said cylindrical body and extending from the othersurface of said plunger disc to the inner surface of the end of saidcylindrical body opposite that through which the plunger rod extends.

By means of the above described present invention, a suspension systemfor vehicles which supports in tension as well as compression, isprovided.

DESCRIPTION OF THE DRAWINGS OF THE PRESENT INVENTION FIG. 1 of thedrawings is a cross section of the apparatus of the present inventionshowing the positioning of a pair of coil springs within the cylindricalbody.

FIG. 2 of the drawings is a cut-away-view of a different embodiment ofthe shock absorbers of the present invention showing the internal partsof the apparatus and including means for attachment of said shockabsorber to a vehicle supporting member, i.e.: the frame, and a vehicleconveyancing member, i.e., a wheel or axle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE PRESENT INVENTION Inorder to more fully describe and to illustrate the preferred embodimentsof the present invention,

reference is made to the accompanying drawings. In the drawings, thesame characters are used throughout to denote like features of thepresent invention.

Referring to the drawings, the shock absorber of the present inventionincludes a cylindrical body 10. This cylindrical body may have a solidwall or may comprise a wall structure as shown particularly in FIG. 1,having an annular space 11 between an inner wall 12 and an outer wall13. The annular space 11 shown in FIG. 1 serves to provide a fluidreservoir for the hydraulic fluid, if any, employed in the shockabsorber. In this embodiment, the shock absorber fluid is exchangedbetween annular space 11 and inner chamber 14 of cylindrical body bymeans of openings 15 provided adjacent the end 16 of cylindrical body10.

In other embodiments of the present invention, no annular space 11 isprovided as a fluid reservoir. While generally used, normal hydraulicfluid in the shock absorbers of the present invention is not necessary.Therefore, the use of such and the reservoir 11 or other similarreservoir with respect to the present shock absorbers is optional.

Referring again to FIG. 1, there is disposed within chamber 14 ofcylindrical body 10 a plunger disc 17, the principal plane of which issubstantially perpendicular to the axis of cylindrical body 10. Plungerdisc 17 is of substantially the same diameter as chamber 14 being ofonly such lesser diameter as is required to permit plunger disc 17 tomove up and down through chamber 14 in slidable but substantially sealedcontract with the inner surface of wall 12 of cylindrical body 10.

Connected to one of the faces 18 of plunger disc 17 is a plunger rod 19which is connected to the face 18 at approximately its center. Plungerrod 19 extends from face 18 substantially along the axis of cylindricalbody 10 through end 20 of cylindrical body 10. An opening 21 in end 20is provided for passage therethrough of plunger rod 19. Opening 21 isadapted, along with plunger rod 19, to permit a slidable and preferably,sealed contact between the surfaces of opening 21 and the outer surfaceof plunger rod 19. When cylindrical body 10 comprises two sections as itmay, one overlapping the other in slidable and sealed contact therewith,plunger disc 17 and plunger rod 19 operate in substantially the samemanner as when cylindrical body 10 comprises a single unit. As usedherein, sealed contact refers to a contact which will at leastsubstantially prevent the passage of hydraulic or lubricating fluidsbetween the contacting surfaces of the members with respect to which theterm is used.

Plunger rod 19 is adapted at its outer end with a connecting member 22as shown in FIG. 2, which permits attachment of the plunger rod 19 toeither a supporting or conveyancing member of a vehicle. In this manner,depending upon choice, the connecting member 22 and thus, plunger rod 19may be connected to the frame of a vehicle or in the alternative, may beconnected to the wheel or axle of the vehicle. In the embodiment of thepresent invention shown in FIG. 2, a shield 23 is provided. Shield 23 isopen at one end and has internal diameter approximately the same butjust larger than the outer diameter of cylindrical body 10. The upperend of shield 23 is closed and attached at approximately the center ofsuch closed end to approximately the outer end of plunger rod 19. Thelength of shield 23 is such that in non-loaded or normal position, itwill partially overlie and surround cylindrical body 10. The purpose ofshield 23 is to protect the sliding surface of plunger rod 19.

The other end 16 of cylindrical body 10 is provided with a connectingmember 24 which permits connection of cylindrical body 10 according tochoice, to either a supporting member or a conveyancing member of avehicle. In operation, connecting member 24 of end 16 usually isconnected to a conveyancing member of a vehicle, i.e., a wheel or axle,while connecting member 22 of plunger rod 19 is connected to asupporting member, i.e., the frame, of the vehicle.

In accordance with the present invention, as illustrated in FIGS. 1 and2, disposed within chamber 14 of cylindrical body 10 are a pair ofcoiled springs, one being designated spring 25 and the other beingdesignated spring 26. Spring 25 is disposed within chamber portion 27 ofchamber 10 which is formed between plunger disc 17 and the end ofcylindrical body 10 opposite plunger rod 19. One end of spring 25 liesin contact with one of the faces 18 of plunger disc 17 while the otherend lies in contact with the inner surface of end 16. While it isunnecessary to connect the terminal end of spring 25 with the innersurface of end 16 and the face of plunger 18, if desired, the terminalend may be fixedly connected thereto.

Spring 26 lies within chamber portion 28 of chamber 10 formed by theother face 18 of plunger disc 17 and the inner surface of end 20 ofcylindrical body 10. Spring 26 surrounds and is substantiallyconcentrically aligned with plunger rod 19. One of the terminal ends ofspring 26 lies in contact with said face 18 of plunger disc 17 while theother terminal end lies in contact with the inner surface of end 20. Aswith spring 25, spring 26 may be connected if desired, at both of theterminal ends to the surfaces with which it is in contact.

While FIGS. 1 and 2 illustrate the use of a coil spring both above andbelow plunger disc 17, the shock absorber of the present invention mayemploy only a single such spring which may be positioned either above orbelow plunger disc 17.

While the coil springs have been shown in a substantially cylindricalform, it is somewhat preferred that for many purposes these springs besomewhat conical in shape. Such conical shape permits greatercompression of the spring without expansion or bending into contact withthe inner wall of chamber 10, thereby substantially reducing wear of thesurface of such inner wall. Of course, the coil springs, as springs 25and 26, may take other shapes but so long as such shapes still permitcompression and expansion, the normal function of the spring, suchshapes are within the spirit and scope of the present invention.

While the shock absorber of the present invention has been shown in FIG.1 as having an annular shock absorber fluid reservoir, such is notrequired. If a shock absorber fluid is to be used, the reservoirtherefor may be placed in an end of the shock absorber rather than inthe annular space shown in FIG. 1. Further, it is not even necessary inall utilities that a shock absorber fluid be used with the shockabsorber of the present invention. Therefore, in such instances theshock absorber fluid reservoir may be dispensed with entirely.

In operation, the shock absorber of the present invention is connectedat one end to a vehicle frame or other body supporting member. At theother end, it is connected to a wheel base, axle or other conveyingmember. Connection may be through connecting member 22 being connectedto a vehicle frame and with connecting member 24 being connected to thevehicle wheel base or axle. By such connection, plunger rod 19 isconnected to the frame with cylindrical body 19 being connected to thewheel base. As the vehicle wheel passes over bumps or as the vehiclebody becomes loaded above normal, plunger rod 19 and thus, plunger disc17 are compressed toward the opposite end 16 of the cylindrical bodythereby compressing spring 25 which in compression, absorbs much of theforce of the downward thrust of plunger disc 17 while simultaneouslyexerting force against the lower face 18 of plunger disc 17 to therebyhelp restore plunger disc 17 to normal position.

If upper spring 26 is connected at its ends as hereinabove discussed,then the compression of coil spring 25 results in expansion of thisspring. Such expansion results in this spring absorbing much of thedownward force of said plunger rod. Also, such expansion of spring 26results in spring 26 exerting upward force upon plunger disc 17 tothereby aid in restoring the plunger disc 17 to normal position.

Particularly with heavy loads, if the rear of the vehicle is forceddownward to thereby compress plunger disc 17 toward the lower end 16 ofcylindrical body 10, then the front of the vehicle rises thereby causingplunger disc 17 to be pulled upward through cylindrical body 10 towardend 20 of such cylindrical body of said shock absorbers on the front ofsaid vehicle. Such movement of plunger disc 17 results in compression ofupper spring 26 which exerts force against the upper face 18 of plungerdisc 17 to restore such plunger disc to normal position. If lower spring25 is attached at its ends as hereinabove discussed, then the upwardmovement of plunger disc 17 will act to expand such lower spring 25thereby causing said lower spring 25 also to exert force downwardly incontraction upon plunger disc 17. Such downward force also works torestore plunger disc 17 to normal position.

By the action of the pair of springs within the shock absorbers ashereinabove described, whether such springs are connected at the endsthereof or not, a vehicle body may be more readily maintained in asubstantially more level position than with conventional shockabsorbers. Also, the ability of such shock absorbers to absorb roadshock is greatly increased.

What is claimed is:

1. A shock absorber comprising a cylindrical body closed at both ends, aplunger disc lying within and across said cylindrical body, said plungerdisc being in sealed but slidable contact with the inner surface of saidcylindrical body, a plunger rod connected at one end to said plungerdisc substantially at the center of said plunger disc, said plunger rodextending through one end of said cylindrical body and being adapted atits other end for connection to a vehicle supporting or conveyancingmember of said vehicle, said cylindrical body being adapted at the endthereof opposite to the end through which said plunger rod extends, forattachme t to the other of aid vehicle su rtin or co veyanci rigmembers, and at least one spr mg sugstantially concentrically alignedwith the axis of said cylindrical body and lying within said cylindricalbody, said coil spring extending between said plunger disc and the innersurface of an end of said cylindrical body and attached at one end tosaid plunger disc and at the other end to said inner surface.

2. The shock absorber of claim 1 wherein said cylindrical body isprovided with a pair of said coil springs, one of said coil springssurrounding said plunger rod and extending between said plunger disc andthe end of said cylindrical body through which said plunger rod extends,the other of said coil springs lying within said cylindrical body andextending from the other surface of said plunger disc to the innersurface of the end of said cylindrical body opposite that through whichthe plunger rod extends.

3. The shock absorber of claim 1 wherein only one said coil springs isprovided.

4. The shock absorber of claim 3 wherein said one coil spring lieswithin the end of said cylindrical body through which said plunger rodoperates.

5. The shock absorber of claim 1 wherein a reservoir for shock absorberfluid is provided, said reservoir being in open communication with theinterior of said cylindrical body.

6. The shock absorber of claim 5 wherein said reservoir is an annularspace surrounding said cylindrical body.

7. The shock absorber of claim 5 wherein said reservoir is in a chamberwithin an end wall of said cylindrical body.

8. The shock absorber of claim 1 wherein said coil spring is cylindricalin shape.

9. The shock absorber of claim 1 wherein said coil spring is conical inshape.

1. A shock absorber comprising a cylindrical body closed at both ends, aplunger disc lying within and across said cylindrical body, said plungerdisc being in sealed but slidable contact with the inner surface of saidcylindrical body, a plunger rod connected at one end to said plungerdisc substantially at the center of said plunger disc, said plunger rodextending through one end of said cylindrical body and being adapted atits other end for connection to a vehicle supporting or conveyancingmember of said vehicle, said cylindrical body being adapted at the endthereof opposite to the end through which said plunger rod extends, forattachment to the other of said vehicle supporting or conveyancingmembers, and at least one coil spring substantially concentricallyaligned with the axis of said cylindrical body and lying within saidcylindrical body, said coil spring extending between said plunger discand the inner surface of an end of said cylindrical body and attached atone end to said plunger disc and at the other end to said inner surface.2. The shock absorber of claim 1 wherein said cylindrical body isprovided with a pair of said coil springs, one of said coil springssurrounding said plunger rod and extending between said plunger disc andthe end of said cylindrical body through which said plunger rod extends,the other of said coil springs lying within said cylindrical body andextending from the other surface of said plunger disc to the innersurface of the end of said cylindrical body opposite that through whichthe plunger rod extends.
 3. The shock absorber of claim 1 wherein onlyone said coil springs is provided.
 4. The shock absorber of claim 3wherein said one coil spring lies within the end of said cylindricalbody through which said plunger rod operates.
 5. The shock absorber ofclaim 1 wherein a reservoir for shock absorber fluid is provided, saidreservoir being in open communication with the interior of saidcylindrical body.
 6. The shock absorber of claim 5 wherein saidreservoir is an annular space surrounding said cylindrical body.
 7. Theshock absorber of claim 5 wherein said reservoir is in a chamber withinan end wall of said cylindrical body.
 8. The shock absorber of claim 1wherein said coil spring is cylindrical in shape.
 9. The shock absorberof claim 1 wherein said coil spring is conical in shape.